Conventionally, for example, a motor driving device executes a PWM modulation by switching switching elements of an inverter circuit to convert a direct-current voltage to an alternating-current voltage, and the motor driving device outputs the alternating-current voltage to motor coils of three phases to drive a three-phase motor. In the motor driving device, a modulation scheme of when the PWM modulation is executed, for example, is selectively switched between a two-phase modulation scheme and a three-phase modulation scheme according to a state of a load driven by a motor (e.g., refer to Patent document 1).